David Treadmill, Microsoft corporate vice president of operating systems, has announced at the company’s Build conference that universal apps are coming to the Windows ecosystem, thanks to Windows RunTime coming to Windows Phone 8.1, PC World has reported. This means that developers will be able to write one app using common code and have it work across phones, tablets, PCs, and even the Xbox One. Developers will also be able to create tailored experiences for each device type, if they so choose, but reuse the bulk of the code for all the apps.